graph [
   directed 1
   node [
      id 1
   ]
   node [
      id 2
   ]
   node [
      id 3
   ]
   node [
      id 4
   ]
   node [
      id 5
   ]
   node [
      id 6
   ]
   node [
      id 7
   ]
   edge [
   source 1
   target 2
   ]
   edge [
   source 1
   target 3
   ]
   edge [
   source 2
   target 4
   ]
   edge [
   source 4
   target 5
   ]
   edge [
   source 2
   target 6
   ]
   edge [
   source 4
   target 6
   ]
   edge [
   source 3
   target 6
   ]
   edge [
   source 5
   target 7
   ]
   edge [
   source 6
   target 7
   ]
   edge [
   source 3
   target 7
   ]
]
